Dark Matter, Through A Glass Darkly

The world we see is an illusion, albeit a highly persistent one. We have gradually got used to the idea that nature’s true reality is one of uncertain quantum fields; that what we see is not necessarily what is. Dark matter is a profound extension of this concept. It appears that the majority of matter in the universe has been hidden from us. That puts physicists and the general public alike in an uneasy place. Physicists worry that they can’t point to an unequivocal confirmed prediction or a positive detection of the stuff itself. The wider audience finds it hard to accept something that is necessarily so shadowy and elusive. The situation, in fact, bears an ominous resemblance to the aether controversy of more than a century ago. …

Nature plays an epistemological trick on us all. The things we observe each have one kind of existence, but the things we cannot observe could have limitless kinds of existence. A good theory should be just complex enough. Dark matter is the simplest solution to a complicated problem, not a complicated solution to simple problem. Yet there is no guarantee that it will ever be illuminated. And whether or not astrophysicists find it in a conceptual sense, we will never grasp it in our hands. It will remain out of touch. To live in a universe that is largely inaccessible is to live in a realm of endless possibilities, for better or worse.

The human condition: to be curious to know it all, but, in our finitude, to be unable to know it all, in part because we cannot perceive it all, much less understand it all.

I’m interested in perception, and how our beliefs both make it easier to see what’s really there, and make it harder to see what’s really there, depending on the context.

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20 Responses to Dark Matter, Through A Glass Darkly

Thank you, Rod.
My list of unread books and articles, unseen films and unheard music was down to only slightly more than I can manage, should I live to be 200.

You just added another one to the pile.

This is the sort of philosophical treatise which I enjoy. Real, sink you teeth into it and think about it material – all the while knowing you just do not and can not know.
Not semantic games, played out in the attempt to impose a pre-ordained conclusion on everyone else (the ‘there’s-no-rights’ discussions whenever women or gays or Negroes get uppity, for example).

God has a sense of humor. He would not otherwise have imbued us with such curiosity and withheld so much intelligence.

I don’t see how dark matter creates epidemiological problems. While it doesn’t reflect light, it does interact gravitationally with light and normal matter. So you can infer its location from orbits of stars or gravity lenses. The situation is like having your eyes closes and mapping a room via touch. Researchers are also close to detecting individual particles as well.

Dark energy is frankly much weirder, but given that dark matter was such a mystery for a while I don’t think it an impenetrable veil. It was also predicted by the cosmological constant in General Relativity so we should have seen it coming.

Although dark energy may give us some insight into the question “Why is there something rather than nothing?” The answer is that empty space isn’t empty and nothing does not exist.

Why should dark matter be a difficult concept? Most things we can observe because of their electromagnetic and other properties (charge, spin); dark matter is something that simply lacks these things. Its existence is inferred–there is a difference between the mass of the universe as predicted by gravitation theory, and the estimated mass of the universe according to observation. As no dark matter has been observed directly, it remains a hypothesis, not an established fact.

If ’tis possible to infer God from the unexplained (and seemingly unexplainable) mysteries of the universe, as some do, inferring the existence of stuff that cannot be detected by telescopes or antennae or the other ways in which we presently can interact with the great beyond outside our solar system, seems hardly remarkable.

A lot of this is part of the modern condition, not the human condition. The big lesson of Copernican astronomy more than that we’re not the center of the universe; it’s that we can’t trust our own lying eyes, which tell us beyond a doubt that the sun revolves around the earth. Nature tricks us. That’s a big part of the modern (post-Copernican) condition.

I got this point from Hannah Arendt, I forget which one of her books, maybe it was The Human Condition.

We were discussing this exact topic last night. The question is, does the real world actually matter or can we simply bumble along on our way in our respect illusory realities which we occupy?

I feel the human condition (i.e. desire to know, or the curiousity) more than most, so I want to know what the real reality is. That said, it’s more than clear that humans can get by well enough believing the world to be and contain all kinds of craziness (pick your favourite bit of nonsense from any era, place, cultural context or what have you. E.g. believers of the Flying Spaghetti Monster and His Noodly Goodness’ role in the creation of the universe 😉 )

For a long time, I’ve been of the view that world that humans actually live in, rather than the real world, is a world that is formed by perception, point of view, perspective and ideology (not political, but more broadly speaking).

Consider the world of a baby, a 5 year old, a 15 year old a 25 year old and a 70 year old, through those 4 lenses. The world that that individual lives in, as lived and experienced by that individual, has changed a great deal due to changes in the lenses through which the individual lives them. Imagine that person male. Now imagine them female. See how it changes? If you can’t see how it changes, you’re not trying very hard or you have such a deep lack of empathy and imagination that I suspect you have some cognitive deficits (no offense intended, just the facts as I see it).

Now, compare what that individual thinks the world is or how an individual experiences their own life, at each stage as compared to what science tells us is actually going on(for example, an x-ray image of yourself vs. what you see through your eyes, vs. what you feel by touch, are you really a solid opaque physical object? That depends doesn’t it?). It’s radically different, and relative to the position and abilities of the observer.

From this divergence of the world as experienced by humans and the world as it actually is (as best as we can tell), a multitude of horrors and mesmerizingly beautiful things arise.

It is a remarkable world we live in, and can open our minds to (or close our minds to as the case may be). Full of wonders, dangers, adventures and excitements for all.

I see what the writer is getting at, but Dark Matter is a terrible example. It seems to me that everything he said about the perception of dark matter could be said about the perception of X-rays. The fact that we don’t know the exact nature of this particle yet is a great puzzle that is solvable, and the characteristics of this stuff are pretty well constrained via a number of independent lines of evidence. Now if the author is just worried that we’ll never perceive it directly (that it is unobservable), and that our inferences about it are theory laden, then everything he is saying could be said about gravitational fields, electromagnetic fields, electrons, neutrons, genes, infrared radiation, neutrinos, and on and on. So what’s so special about dark matter?

On an epistemological note, Indian Buddhist philosophy was greatly concerned with the question of how pre-existing cognitive structures (whether conceptual like beliefs or nonconceptual like cataracts) influence the perceptual process. Probably the most important feature of their epistemological theory was the assertion that, ultimately, subject-object phenomenological duality is nothing more than an error which obscures reality. So in a sense even our most “veridical” and scientific perceptions are mistaken, at least to the extent that they are dualistically-structured.

This is interesting; Dark Matter and Dark Energy probably exist and we cannot detect them.
It reminds me of a conversation I had with a friend of mine who said he was a “staunch atheist” and would only rely on reason.
I asked him, “well if you use reason to arrive at a conclusion based on imperical facts derived from your senses, how can you be sure of anything? We evolved with just 5 senses. Is there a possibility that our senses do not capture all reality? Maybe there is a spirit world (you atheists may laugh at this point) that we just cannot detect. Do you grant me that posssibilty?” “Yes” was his answer. “Good, because we call that faith”.

I, too, am not sure why Dark Matter and Dark Energy are good examples. They’re like the photoelectric effect or the results of the Michelson-Morley experiment: something is happening that we can detect which does not fit into our current model of understanding, and we are trying to figure out what is causing it so that we can update our model.

A more interesting case is the fact that in several billion years, the expansion of the universe will make it impossible to perceive most of the galaxies in the universe meaning that it will be close to impossible to make the observations we are now able to make which allow us to see evidence of the Big Bang (at least in the way we can see now).

This is interesting; Dark Matter and Dark Energy probably exist and we cannot detect them.

This is not true otherwise scientists wouldn’t have proposed them.

Dark matter doesn’t interact with the electromagnetic force, but it can be detected by the other forces such as gravitation or the nuclear forces. So it has visible effects.

Dark energy was detected by the change in acceleration of galaxies apart from one another over time. Since light takes time to get to us, we can effectively look back in time and see how this repulsive force acted over time. The increase in acceleration matches the expansion of space which would be expected if empty space contained a repulsive energy.

Is there a possibility that our senses do not capture all reality? Maybe there is a spirit world (you atheists may laugh at this point) that we just cannot detect. Do you grant me that posssibilty?” “Yes” was his answer. “Good, because we call that faith”.

But you know, this is a very clever game, and I don’t mean that pejoratively. “God” or “the spirit world” is totally ineffable, undetectable, etc. in principle, yet we have people who are somehow certain that they know what it wants and that everyone else needs to follow its commands.

I think the faith The Dean is talking about can absolutely go no further than Deism, because a God that can communicate with people is detectable. We could start by finding out what physical forces he’s using to make changes in people’s brains when he does communicate.

I am more intruigued by the discussions and research as it pertains to ‘black holes.” Dark matter is such a new area of study, I am not sure whether is a source of energy at all or exists. Maybe I have this wrong, but dark matter through the haze of air and sky looks blue in the morning and black at night.

” . . . but then I will know even as I am fully known.”

I am more intrigued with what we don’t know about black holes —- a condition in which even infinity looses it’s value.

Oh come on, dark matter is simply matter that present technology is unable to measure completely. This is why I favor ongoing immigration from India and China- they will do our scientific and engineering work while Americans get all metaphysical and mystical.

I find it hilarious when non-physicists use stuff like “dark matter” or “dark energy” or “black holes” to go all woo-woo about Meaning and Philosophy and The Meaning Of All This. (Or the Higgs boson, which someone called The God Particle.)

Math. It’s all math. And observations. No need to drag the supernatural into it.

A great discussion here, and I enjoy all of the opinions. On a serious note though, does anyone out there believe that reality is just what we see, hear, taste, feel, and smell?
I may be wrong about a God that has a greater (actually the greatest) inelligence but I don’t think so. I believe that the human mind can only reason, deduce, and apply logic within the limits that have been imposed on the evolved brain (physical) and mind (mental). We accept the fact that there are beings with less intelligence i.e. animals, but we become arrogant when someone suggests that there may be superior beings that we cannot detect with our five senses. I remember a short quote from Christian apologetics, “if we could understand God, he wouldn’t be God”.

A neutrino is actually a good model for dark matter particles. It has an extremely small mass, but no electric charge, so it can’t interact with normal matter via the electromagnetic force. However, it can interact via the weak nuclear force, so that sounds just like dark matter to me. Since the mass distribution of atoms is lopsided with most of the volume is taken up by lightweight electrons, a neutrino is effectively invisible and free to pass through normal matter which is effectively empty space to it. If it wasn’t for their occasional weak nuclear interactions with the nucleus we would never know they’re there.

For me where things start getting weirder is that protons and neutrons are composite particles too, and while they have a radius, their quarks are effectively point particles. So they’re mostly empty space too! It’s like all matter is a fog of fields, but nothing is solid at all.